Linolenic acid deficiency: changes in fatty acid patterns in female and male rats raised on a linolenic acid-deficient diet for two generations.

Rats were fed for two generations a purified, linolenic acid-deficient diet in which the only source of lipid was purified methyl linoleate. This diet contained about 38 mg linolenic acid/kg diet. Control rats were given the same diet supplemented with methyl linolenate (2,500 mg/kg diet). Male and female rats ranged in age from weaning pups to adults. Lipids were extracted from liver, brain, kidney, spleen, heart, muscle, gastrointestinal tract, lung, ovary, testis, adrenal, plasma, erythrocytes, retina, and adipose tissue. Fatty acids of major phospholipid classes (choline phosphoglycerides, ethanolamine phosphoglycerides, and mixed serine phosphoglycerides plus inositol phosphoglycerides) or of total lipid extracts were measured by gas liquid chromatography. Growth rates and organ weights were similar in control and linolenic acid-deficient rats. The major effect of the deficiency was to lower the proportions of n-3 fatty acids, especially 22:6 n-3, in all the organs analyzed. Docosahexaenoic acid (22:6 n-3) was mainly replaced by 22:5 n-6 in deficient rats. The greatest changes in composition were found in brain, heart, muscle, retina, and liver.